TRANSCEIVING INTERFACE DEVICE FOR RECEIVING TELEPHONE SERVICE IN ASYNCHRONOUS TRANSFER MODE AND METHOD THEREOF

摘要

PURPOSE: A transceiving interface device for receiving a telephone service in an asynchronous transfer mode is provided to convert telephone data having constant channels and frames into compression data having variable sizes, and to change the compression data into data having an AAL2(ATM Adaptation Layer2) form of the asynchronous transfer mode. CONSTITUTION: Many E1 compressors(21) compress one E1 frame transmitted from a PSTN(Public Switched Telephone Network) in lossless real time, and generate variable data smaller than 32 octets. An AAL2(ATM Adaptation Layer2) multiplexer(22) discriminates from which E1 transmission line the compressed variable data comes, with a CID(Channel Identification). The AAL2 multiplexer(22) multiplexes the compressed variable data to AAL2 CPS-PDUs(Common Part Sublayer-Protocol Data Units) every 125 micro second. An ATM cell converter(23) sequentially stores the AAL2 CPS-PDUs in ATM cells, and fills the rest space with a PAD, then makes the AAL2 CPS-PDUs ATM cells. A DS(Digital Signal)-n/STM(Synchronous Transfer Mode)-n converter(24) converts the ATM cells into DS-n signals or STM-n signals, to transmit the ATM cells through an ATM transmission line.